What's the difference between a process and a process image?

From what I understand, a process image is an image of a process taken when memory is allocated to it before execution. This happens because, when multitasking, the kernel needs to re-enter the process where it left off. If the process were to be changed in mid execution, bad things could happen so the operating system makes a read-only version of the process and uses that during execution.

Here's a webpage with more details on process images